[exodust]

> Why are all buildings the same? Light switches are often in similar places...

That's not true at all. Buildings are often very different from one to the other in both exterior design and internal layout.

In my experience, even light switches in commercial buildings are often in very different spots to where you'd expect, relative to a normal residential house. This is partly due to lights being switched on from one central area, and not being something normal visitors or workers of the building need to use. These are fittings anyway, not "the building".

Actual building architecture and interior design is very diverse, so your analogy here using buildings is not a good one to compare with the often identical website layouts seen everywhere.